Critical role of intercalated water for electrocatalytically active nitrogen-doped graphitic systems
| Autor: | Piotr Zelenay, Joseph H. Dumont, David A. Cullen, Geraldine M Purdy, Edward F. Holby, Ulises Martinez, Nathan H. Mack, Akhilesh Kumar Singh, Kateryna Artyushkova, Andrew M. Dattelbaum, Aditya D. Mohite, Gautam Gupta, Manish Chhowalla, Plamen Atanassov, Karren L. More |
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| Jazyk: | angličtina |
| Rok vydání: | 2016 |
| Předmět: |
inorganic chemicals
Nitrogen Heteroatom Materials Science Nanotechnology 02 engineering and technology Electrolyte 010402 general chemistry 01 natural sciences Catalysis law.invention X-Ray Diffraction law Spectroscopy Fourier Transform Infrared Electrochemistry Graphite Dissolution Research Articles Multidisciplinary Dopant Graphene Chemistry intercalated water SciAdv r-articles Water Electrocatalysts Oxides Models Theoretical 021001 nanoscience & nanotechnology 0104 chemical sciences oxygen reduction Oxygen Chemical engineering Solvents graphene oxide 0210 nano-technology Selectivity Oxidation-Reduction Research Article |
| Zdroj: | Science Advances |
| ISSN: | 2375-2548 |
| Popis: | Removal of intercalated water within graphitic sheets is critical to achieving high-performing oxygen reduction reaction catalysts. Graphitic materials are essential in energy conversion and storage because of their excellent chemical and electrical properties. The strategy for obtaining functional graphitic materials involves graphite oxidation and subsequent dissolution in aqueous media, forming graphene-oxide nanosheets (GNs). Restacked GNs contain substantial intercalated water that can react with heteroatom dopants or the graphene lattice during reduction. We demonstrate that removal of intercalated water using simple solvent treatments causes significant structural reorganization, substantially affecting the oxygen reduction reaction (ORR) activity and stability of nitrogen-doped graphitic systems. Amid contrasting reports describing the ORR activity of GN-based catalysts in alkaline electrolytes, we demonstrate superior activity in an acidic electrolyte with an onset potential of ~0.9 V, a half-wave potential (E½) of 0.71 V, and a selectivity for four-electron reduction of >95%. Further, durability testing showed E½ retention >95% in N2- and O2-saturated solutions after 2000 cycles, demonstrating the highest ORR activity and stability reported to date for GN-based electrocatalysts in acidic media. |
| Databáze: | OpenAIRE |
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